1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Description of the Related Art
As a display device for an information communication terminal such as a computer or a television, a liquid crystal display device has been extensively used. The liquid crystal display device changes an electric field to change an orientation of a liquid crystal composition confined between two substrates, and controls the degree of transmission of a light transmitted through those two substrates and the liquid crystal composition to display an image. In order to change the electric field, the liquid crystal display device applies a voltage corresponding to a gradation value of each pixel to a pixel electrode through a pixel transistor of each pixel.
The liquid crystal composition has a property that the orientation becomes fixed when a voltage of the same polarity continues to be applied to the liquid crystal composition for a long time, which results in a residual image phenomenon. Also, the transistor also has a property that a threshold value for rendering the transistor conductive becomes shifted when being continuously applied with a voltage of one polarity. For that reason, in the liquid crystal display device, it is general to display an image by so-called “inversion driving” which drives while inverting the polarity of electric charge.
JP 2008-256811 A discloses a so-called dot inversion driving that prevents flicker.